Chocolate boost A new study suggests a cocoa drink a day could help boost the efficiency of your brain's working memory, but it's too early to say for sure.

The randomised double-blind placebo controlled trial, led by Dr David Camfield of the Centre for Human Psychopharmacology at Swinburne University, was funded by a large chocolate manufacturer.

"It does provide preliminary evidence that [cocoa flavanols] can help people to do cognitive tasks more effectively," says Camfield, whose research is published in the journal Physiology & Behaviour.

Flavanols are chemicals found in plant foods, including grapes, apples, tea and cocoa and have been linked to a range of health benefits, says Camfield.

This latest study looked at the effect of cocoa flavanols on spatial working memory, which holds information in the brain and makes it available for further processing

Camfield says spatial working memory declines rapidly as people age.

His study involved 63 middle-aged volunteers aged between 40 and 65 years, who were asked to drink a chocolate drink each day for 30 days before being tested.

"We looked at brain imaging while people were doing a spatial working memory task," says Camfield.

Screen tests

In the task, volunteers looked at dots displayed on a screen. Then for about 3 seconds, the screen went blank and during that time the participant had to hold in their memory the location of the dots.

They were tested several times to see whether they could remember where the dots were.

The volunteers were divided into three groups. One group had a drink containing 500 milligrams of cocoa flavanols, a second group had a drink with 250 milligrams of cocoa flavanols and a third group had a placebo drink.

None of the groups knew exactly what they were drinking.

The tests were carried out before and after the 30-day treatment period and each time the researchers carried out imaging to check the brain's activation.

"We didn't find any differences in terms of accuracy or reaction time in terms of task itself, but we found differences in the brain activity," says Camfield.

Less brain power

Camfield says the frontal and posterior parietal areas of the brain involved in the task were less active in those consuming the cocoa flavanols.

"It's suggests that they were processing the tasks more efficiently when they were taking the cocoa flavanols," he says.

"I guess you could say they weren't working as hard doing the same task."

Camfield says the findings also suggest cocoa flavanols may guard against brain fatigue, but emphasises more research needs to be done.

The Centre for Human Psychopharmacology focuses on researching nutraceuticals, which are natural alternatives to pharmaceuticals, for an ageing population. The centre receives funding from industry as well as the Australian Research Council.

He says while the study was funded by a chocolate company, it had no influence on how the study was carried out.

"They didn't have a role in how we did the science or analysed the data," says Camfield.

"Promising" findings

Sydney-based nutrition consultant, Nicole Senior says the findings are "promising" and add to other evidence showing chemicals in cocoa are good for the heart, but she says it's important to remember the pros and cons of chocolate.

"Chocolate carries with it a lot of kilojoules in a small and delicious package. Dark cocoa powder tops the list of cocoa foods with minimum nutritional downsides, which you can make into a drink," she says.

"Dark chocolate is better than milk chocolate because it contains higher cocoa solids and antioxidant content and is also stronger in flavour and more satisfying so you can be happier with a small portion."

Useful insights

Dr Garry Egger who is a professor of health and human sciences at Southern Cross University says the study does not prove that a cup of hot chocolate a day will boost your memory.

"This is just a short-term study," says Egger.

In general, he is not a fan of the idea of people selectively eating particular foods to boost their health and abilities.

But, he says, the research is part of general trend towards testing the impact of isolated foods on human health, which provides useful insights into what makes up a healthy diet.

Egger says cocoa is an ancient food and has also been shown to reduce inflammation.

He says recent evidence suggests unprocessed foods that humans have evolved with over the long term are generally showing better effects on the body when tested in isolation.